Enhanced efficiency of multicrystalline silicon solar cells made via UV laser texturing

Multicrystalline silicon (mc-Si) solar cells were developed by using a direct laser texturing method. Approximately 10-μm-deep and 10-μm-diameter cone-shaped grooves, with an aspect ratio (determined by the depth-to-diameter ratio) of one, were produced on the wafer’s surface by using a 355-nm-wavelength ultraviolet (UV) laser process. After slag removal and chemical etching, V-shaped cross-sectional microstructures were regularly arranged in a honeycomb disposition on the surface. Compared to the mc-Si solar cell textured by using isotropic acidic etching, the surface reflectance was reduced to 3.3% and the short-circuit current increased to 0.8 mA/cm² when the cell was treated with UV laser ablation. The solar cell values were achieved from the increased electron-hole pairs (EHPs) generated by the enhanced bouncing of incident light, which was aided by the V-shaped microstructures. The cell efficiency of a UV-laser-textured cell was improved to 16.1% compared to the 15.5% for an acidic-solution-textured cell.